Diego Fernández (c. 1520–c. 1581) was a Spanish adventurer and historian. Diego Fernández may also refer to: Diego Fernández of Oviedo (fl. 1020–c. 1046), Count of Asturias and father of Jimena Díaz, the wife of Rodrigo Díaz de Vivar, el Cid Diego Fernández de Ovando, Spanish military and nobleman, knight of the Order of Alcántara in 1338 Diego Fernández de la Cueva, 1st Viscount of Huelma (died 1473), Spanish nobleman Diego Fernández de Córdoba y Arellano, 1st Marquis of Comares (1463–1518), Governor of Oran and Mazalquivir and Viceroy of Navarre, Diego Fernández de Proaño, Spanish explorer and conquistador Diego Fernández de Cáceres y Ovando (died 1487), Spanish military and nobleman Diego Fernández de Córdoba, 1st Marquess of Guadalcázar (1578–1630), Viceroy of Mexico, 1612–1621, and Viceroy of Peru, 1622–1629 Diego Fernández (harpsichord maker) (1703–1775), harpsichord maker of the Spanish court Diego Fernández de Cevallos (born 1941), Mexican politician affiliated to the conservative National Action Party See also Diogo Fernandes Diogo Fernandes (count)